The trend in many industries to make devices smaller has led to an explosion in the development of techniques that can be used to manufacture micrometer- and, more particularly, nanometer-scale features on surfaces. One such technique is based on the concept of dewetting, which generally refers to processes where solid or liquid films located on a given surface break down into discrete droplets or islands on the surface in order to reduce the free energy of the system.
Regardless of whether the initial film is a solid or liquid, it can be thermodynamically metastable at low thicknesses. This is, at least in part, due to the fact that the surface energy of the film is higher than that of the interface between the film and the substrate, and higher also than that of the substrate itself. When energy (e.g., thermal energy, electromagnetic energy, plasma energy, and the like) is introduced to such a film, the activation barrier against atomic diffusion can be overcome. Under such conditions, the atomic diffusion causes the film to dewet (i.e., transform into discrete islands on the surface of the substrate).
Prolonged exposure to the dewetting energy source can lead to decreased island sizes that can be desirable for certain applications. Unfortunately, sustained exposure to the dewetting energy source can also adversely affect the underlying substrate or other device components. By way of illustration, to dewet a metal film from a semiconductor substrate, high temperatures are often used. These high temperatures can damage the semiconductor substrate itself and/or any device components that are disposed thereon and/or in the immediate vicinity. Such damage can include melting, decomposition, oxidation, and the like.
Another drawback associated with existing dewetting methods is the difficulty obtaining continuous starting films at low thicknesses needed in order to achieve small (i.e., micrometer- or nanometer-scale) island sizes. For example, discontinuous starting films can result in inefficient dewetting, because the film can partially wet previously uncovered/unwetted areas of the substrate while also dewetting other (covered/wetted) areas. To combat this, thicker films are often used. Unfortunately, thicker films, while providing more efficient dewetting, result in larger islands and/or larger surface coverage areas. For applications where smaller island sizes are needed, this can be undesirable.
There accordingly remains a need for technologies that provide improved dewetting of surfaces with the ability to achieve smaller feature sizes. It would be beneficial if such technologies could be implemented without adversely affecting the substrates that are dewetted. It is to the provision of such technologies that the present disclosure is directed.